Nowadays, there are few people left who have not heard about HIV and AIDS, but not everyone understands the difference between these concepts.
What is HIV and what is AIDS?
HIV is a human immunodeficiency virus that, upon entering the body, destroys the immune system, which leads to critically low resistance to the effects of various pathogenic agents.
AIDS (human immunodeficiency syndrome) is a direct pathological process in the active phase of development of HIV infection. In this case, those infected exhibit symptoms of various serious diseases caused by suppression of the immune system, which result in death.
HIV infection can occur through several routes.
- As a result of unprotected sexual intercourse (this includes vaginal, oral and anal sex).
- Through blood (with intravenous injections with a contaminated needle and blood transfusions from an infected donor to a healthy person).
- Intrauterine path (from mother to fetus).
- When breastfeeding (from an infected mother to her child).
HIV and AIDS - what's the difference?
First of all, it must be said that HIV and AIDS are different stages of the same process. More precisely, HIV-positive status indicates the fact that a person is infected with the immunodeficiency virus, and AIDS is already a clear confirmation of the active development of this virus in the body.
The average life expectancy of an HIV-infected person can be several decades without the occurrence of major manifestations of immune system dysfunction. If the disease has passed into the AIDS phase, then, most likely, in a few months (depending on the severity of the current condition) the patient will die.
Another significant difference between HIV and AIDS is that when a carrier of the virus is detected, a person undergoes therapy, the essence of which is to stimulate the activity of the protective mechanisms of the immune system, and the treatment of AIDS consists of reducing the intensity of the main manifestations of serious illnesses that have developed against the background of the destruction of the immune system. systems.
To fight infection, drugs containing macrophages and T-lymphocytes are introduced into the body - these are immune cells that are targets for HIV. We can say that the essence of HIV treatment comes down to preventing the development of AIDS, when the effect on the immune system will no longer be meaningful.
Important!
The life of the immunodeficiency virus is possible only in the cells of the human body. Outside this environment, he dies very quickly. This is why HIV does not spread through personal contact.
Stages of HIV and AIDS
After the immunodeficiency virus enters the blood, the human body undergoes certain pathological changes, which include several main stages.
- Incubation period. This is the period of time that lasts from the moment of infection until the first signs of the disease appear in the patient. Depending on the state of the person’s immune system initially, this phase can last from several days to several weeks.
- Installation period. After the virus has entered the body and infected the cells of the immune system, a fairly large amount of time may pass before the infected person begins to experience various pathological phenomena. Sometimes infected people periodically experience isolated signs of retroviral syndrome, but they are usually not given due importance. Such symptoms include chronic fatigue, decreased performance, and aches throughout the body.
- Final period. In this case, the immunodeficiency virus enters the active phase of its life. The human immune system is in an extremely depressed state, so the body cannot resist infectious agents. At this time, the carrier of the virus may feel constant malaise, fever, suffer from constipation and excessive sweating, especially at night. A person with AIDS rapidly loses weight. Also a characteristic sign of decreased immune activity is multiple candidiasis (fungal infections). At the same time, he can become infected with any infection, be it pneumonia or tuberculosis, and die from the consequences of the infection developing in the body. In the last stages of AIDS, against the background of a critically weakened immune system, the infected person may begin to form malignant neoplasms.
Conventionally, several stages of the development of AIDS can be distinguished.
- Mononucleosis-like syndrome.
- Generalized lymphadenopathy.
- Pre-AIDS.
- Stage of vivid clinical manifestations.
In the absence of adequate therapy, signs of AIDS appear in a person within 10-13 years after infection with the immunodeficiency virus. With timely detection of the disease and treatment of HIV, the onset of AIDS can be delayed for several decades, or even prevented.
What's worse: HIV or AIDS?
The answer to this question is obvious. AIDS is an irreversible process that cannot be cured. Unfortunately, when the disease enters this stage of development, the patient’s condition can only be alleviated by reducing the intensity of the symptoms of the disease that have arisen against the background of a critically weakened immune system.
Just 15-20 years ago, HIV-positive status was practically a death sentence for a person. However, now, thanks to the rapid development of medicine, many infected people around the world receive treatment that allows them to lead an active lifestyle and even give birth to healthy children.
With timely diagnosis of HIV infection, an infected person has the opportunity to live a full life for many years to come, provided he receives therapy.
And most importantly, don’t turn away from people if they have HIV. Support and do not be afraid to become infected through touch and communication. Many have been HIV positive since childhood; it is not their fault that fate decreed it this way. Be understanding!
According to the World Health Organization, more than 42 million people on Earth are infected with the human immunodeficiency virus. Every day another 14 thousand people are added to this terrifying figure. And every second on the planet one person dies from AIDS. The majority of HIV-infected people are young people under the age of 30. Over the past 25 years, about 25 million people have died from AIDS, more than one and a half million of them were children. AIDS is called the plague of the 20th century.
AIDS (acquired immunodeficiency syndrome) is the final phase of the disease. First comes HIV, the human immunodeficiency virus. Having penetrated the human body, it affects the immune system, which, as a result of defeat by a retrovirus, weakens to such an extent that a common runny nose can bring a person to the grave in the shortest possible time.
Research has shown that the virus is especially active in the first weeks after infection. It can manifest itself as a slight cough, slight fever, headache, sweating, diarrhea and simply feeling unwell. And a person, unaware of the seriousness of the disease, is in no hurry to see a doctor. The virus, meanwhile, continues its destructive work of suppressing the immune system's ability to fight disease and ultimately causing severe illness. This may be untreatable pneumonia, blood poisoning, skin lesions or cancer.
Many people are concerned about how one can become infected with AIDS?
The virus is transmitted from one person to another through unprotected sexual contact, especially often during homosexual sex; from a sick mother to her child during childbirth and when feeding with contaminated milk. But the main route of transmission of infection remains intravenous drug use, when several drug addicts use the same syringe.
What are the measures to prevent HIV/AIDS?
Maintaining a healthy lifestyle, choosing a permanent sexual partner, preventing injection drug use. To prevent infection of newborns from HIV-infected pregnant women, the main measure is to receive chemoprophylaxis for pregnant women, for which it is necessary to register in a timely manner at the antenatal clinic.
Can AIDS be cured?
Unfortunately, AIDS still cannot be cured. All available drugs only slow down the course of the disease and prolong the lives of patients by several years.
To more effectively combat the spread of infection, it is necessary for each person to take personal responsibility for their health, be committed to a healthy lifestyle, and give up alcohol and drug use.
HIV is the abbreviated name for the human immunodeficiency virus, i.e. a virus that attacks the immune system. HIV lives and multiplies only in the human body.
When infected with HIV, most people do not experience any sensations. Sometimes, a few weeks after infection, a flu-like condition develops (fever, skin rashes, swollen lymph nodes, diarrhea). For many years after infection, a person may feel healthy. This period is called the latent stage of the disease. However, it is wrong to think that nothing happens in the body at this time. When a pathogen, including HIV, enters the body, the immune system mounts an immune response. She tries to neutralize the pathogen and destroy it. To do this, the immune system produces antibodies. Antibodies bind to the pathogen and help destroy it. In addition, special white blood cells (lymphocytes) also begin to fight the pathogen. Unfortunately, when fighting HIV, all this is not enough - the immune system cannot neutralize HIV, and HIV, in turn, gradually destroys the immune system.
The fact that a person has become infected with a virus, i.e. becoming HIV-infected does not mean that he has AIDS. It usually takes a long time before AIDS develops (on average 10-12 years).
AIDS
The virus gradually destroys the immune system, reducing the body's resistance to infections. At a certain point, the body’s resistance becomes so low that a person can develop infectious diseases that other people practically do not get sick with or get sick extremely rarely. These diseases are called "opportunistic".
AIDS is spoken of when a person infected with HIV develops infectious diseases caused by the ineffective functioning of the immune system destroyed by the virus.
AIDS is the last stage of development of HIV infection.
AIDS – acquired immunodeficiency syndrome.
Syndrome- this is a stable combination, a set of several signs of the disease (symptoms).
Acquired- means that the disease is not congenital, but developed during life.
Immunodeficiency- a condition in which the body cannot resist various infections.
Thus, AIDS is a combination of diseases caused by insufficient functioning of the immune system due to its defeat by HIV.
Where did the virus come from?
Unfortunately, there is no clear answer to this question. There are only hypotheses. Each of them has its own justification, but in the scientific world they all continue to remain only assumptions - possible and, for some, very controversial versions of what happened.
The very first hypothesis about the origin of HIV is related to monkeys. It was expressed more than 20 years ago by the American researcher B. Corbett. According to this scientist, HIV first entered the human bloodstream in the 30s of the last century from chimpanzees - possibly through an animal bite or during the process of cutting up a carcass by a person. There are serious arguments in favor of this version. One of them is that a rare virus was actually found in the blood of chimpanzees, capable of causing a condition similar to AIDS when it enters the human body.
According to another researcher, Professor R. Garry, AIDS is much older: its history goes back from 100 to 1000 years. One of the most serious arguments confirming this hypothesis is Kaposi’s sarcoma, described at the beginning of the 20th century by the Hungarian doctor Kaposi as “a rare form of malignant neoplasm,” which indicated the presence of an immunodeficiency virus in the patient.
Many scientists consider Central Africa to be the birthplace of AIDS. This hypothesis, in turn, is divided into two versions. According to one of them, HIV has long existed in areas isolated from the outside world, for example, in tribal settlements lost in the jungle. Over time, as population migration increased, the virus broke out and began to spread rapidly. The second version is that the virus arose as a consequence of increased radioactive background, which was recorded in some areas of Africa rich in uranium deposits.
Relatively recently, another hypothesis appeared, belonging to the English researcher E. Hooper: the virus appeared in the early 50s of the twentieth century as a result of an error by scientists working on the creation of a polio vaccine. The mistake was that chimpanzee liver cells, supposedly containing a virus similar to HIV, were used to produce the vaccine. One of the strongest arguments in favor of this hypothesis is the fact that the vaccine was tested precisely in those areas of Africa where the highest level of infection with the immunodeficiency virus has been recorded to date.
Stages of development of HIV infection
Incubation period of HIV infection
The period from the moment of infection to the appearance of clinical manifestations of the disease. Lasts from 2 weeks to 6 or more months. At this stage, even testing may not detect the virus, but HIV infection can already be transmitted from the infected person to other people.
Stage of "Primary manifestations"
This stage may be asymptomatic or accompanied by fever, swollen lymph nodes, stomatitis, spotty rash, pharyngitis, diarrhea, enlarged spleen, and sometimes encephalitis. This usually lasts from a few days to 2 months.
Latent stage
The disease may not manifest itself in any way, but HIV continues to multiply (the concentration of HIV in the blood increases), and the body is no longer able to produce the required number of T-lymphocytes - their number slowly decreases. The latent stage can last from 2–3 to 20 or more years, on average 6–7 years.
Stage of secondary diseases
Due to the ongoing active increase in the concentration of the virus in the blood and the decrease in T-lymphocytes, the patient begins to develop various opportunistic diseases, which the immune system is no longer able to resist due to the rapidly decreasing number of T-lymphocytes.
End stage (AIDS)
The last and final stage of HIV infection. The number of protective cells (T-lymphocytes) reaches a critically low number. The immune system can no longer resist infections, and they quickly deplete the body. Viruses and bacteria affect vital organs, including the musculoskeletal system, respiratory system, digestive system, and brain. A person dies from opportunistic diseases that become irreversible. The AIDS stage lasts from 1 to 3 years.
Course and prognosis of HIV infection
When a person finds out that he has HIV infection or AIDS, the first questions he is most often asked are: “How long do I have to live?” and “How will my illness progress?”
Since HIV infection and AIDS progress differently for everyone, these questions cannot be answered unambiguously. But some general information can be highlighted.
People with HIV infection and AIDS these days are living much longer than before.
Treatment of HIV infection and AIDS is becoming increasingly successful. With treatment, people with HIV infection feel healthy for a longer period of time, and AIDS patients live longer and, compared to previous years, not only have fewer manifestations of the disease, but it is much easier.
At the beginning of the epidemic (1981-1986), AIDS developed in patients on average 7 years after infection with the virus. After this, the person could live for about another 8-12 months. Since the introduction of combination antiretroviral therapy in 1996, the lives of people living with HIV and AIDS have become much longer. Some people who develop AIDS may live 10 years or longer.
First of all, such progress is ensured by drugs that act on the virus itself - antiretroviral drugs.
Life is also extended due to the fact that with the help of combination therapy it is possible to prevent the development of many opportunistic infections, which are the direct cause of death in HIV infection.
The search for new treatment methods continues. There is no doubt that even more drugs effective in combating this infection will soon become available.
Content:
In the modern world, with sufficiently developed medicine, there are diseases that cannot be treated. The most common disease that has claimed a large number of lives is HIV (human immunodeficiency virus). In Russia alone, about 800 thousand people are carriers of this infection. Among the infected people there are men, women and children. This virus is scary for everyone, but it is most dangerous for women, since they have a higher risk of infection and can pass the infection on to their child.
Symptoms of HIV in women appear with some differences.
Therefore, at the first doubt about your health, you should immediately consult a doctor and get tested.
Is it possible to become infected with HIV through household methods?
The more dangerous the disease, the more frightening a person is at the thought that he can become infected with it. HIV is transmitted through contact between the mucous membranes of a healthy and sick person (sperm, blood, cervical mucus). This virus does not spread through household means.
Another common question is whether HIV is transmitted through kissing. Doctors give a negative answer. The likelihood of contracting an infection in this situation, in the absence of wounds in the mouth and tongue of both partners, is zero.
Groups at risk of contracting the virus
The following population groups are at high risk of contracting HIV infection:
- drug addicts who use drugs by injection (through a syringe needle);
- women and men during unprotected sexual intercourse, as well as those practicing oral and anal sex;
- children whose mothers are HIV positive;
- doctors who, in their specialization, come into contact with infected people or tissues (diagnostic laboratory assistants, gynecologists, obstetricians, surgeons);
- persons in need of blood transfusion;
- people leading an immoral lifestyle.
In most cases, HIV is transmitted through needles among drug addicts and through unsafe sex.
Symptoms of having a virus
A woman has a greater risk of acquiring HIV. Therefore, you should always monitor your health and not do anything rash.
If a circumstance has occurred that causes you to doubt your HIV status, you should take a blood test (enzyme-linked immunosorbent assay detects the presence of antibodies to the virus). But by nature, HIV does not manifest itself in the first days. Most people develop antibodies 3 months after infection, while others develop antibodies after 6 months. Therefore, 100% results will be achieved only in six months.
Before this period expires, you should pay attention to your well-being. Symptoms can be detected after a few weeks, or you may not feel any deviations from the norm for 10 years. The first symptoms appear as:
- enlarged lymph nodes;
- excessive sweating at night;
- lethargy, drowsiness and fatigue;
- lack of appetite;
- severe depression for no reason;
- the presence of constantly elevated body temperature.
Without undergoing specific therapy to combat the virus, the infection will progress, immunity will weaken and health will deteriorate. Symptoms of complications of the disease may appear, such as:
- vaginal infections;
- presence of abnormalities in smear analysis;
- the appearance of herpes, warts, ulcers on the labia majora;
- red spots on the body;
- white spots on the oral mucosa.
Even if a woman has these symptoms, they do not confirm the presence of the virus. Such painful manifestations may be signs of other infections (ARVI). Therefore, there is no need to panic.
During the six-month period, from the date of suspected infection or the onset of symptoms, you should avoid sexual and other contacts in which you can transmit the infection to a healthy person, you should not be a donor, and it is advisable to delay pregnancy.
Life after infection
If preliminary and confirmatory tests reveal that you have HIV infection, then you should not take extreme measures. Modern medicine makes it possible to live with such a diagnosis and have the same rights as healthy people, but undergoing treatment.
A woman who does not have children must understand all the responsibility. Having HIV does not prevent you from having a child. And HIV patients give birth to healthy children, and, in addition, scientists are looking for a way to cure HIV in newborns.
During pregnancy, women are prescribed antiretroviral drugs. They reduce the viral load to such a level that during a normal pregnancy and uncomplicated childbirth, the child is born healthy. Women are prohibited from giving birth on their own, since the highest percentage of children becoming infected is during childbirth. They undergo a caesarean section. Also, mothers should not breastfeed their children for the same reason.
A person with such a diagnosis needs to communicate correctly with healthy people. You can't put others in danger. If a woman decides to become pregnant naturally, she must inform her partner about her situation. Otherwise, this is a crime in Russia, it is criminally punishable (Article 122 of the Criminal Code of the Russian Federation).
The path from HIV to AIDS
All HIV-infected people should be monitored by doctors and undergo therapy to combat the virus. If the disease is detected in a timely manner and measures are taken to treat it, then such a person can live for decades.
If HIV is left untreated, it develops into acquired human immunodeficiency syndrome (AIDS). This is the last stage of the disease. Against the background of AIDS, other infectious diseases develop, such as tuberculosis, pneumonia, meningitis, and herpes. Any infection (even a cold) in AIDS patients leads to serious consequences, since their immune system is not able to cope with bacteria and viruses. AIDS can be fatal; there are more than 100 thousand such cases in Russia.
HIV is one of the most dangerous diseases of the 21st century. A cure for it still cannot be found. Therapy only slows down and stops the development of infection. Therefore, you need to take care of yourself and your health.
Avoid contact with drug addicts, try to have an intimate life only with regular and trusted partners, sex should be protected. There is no need to be embarrassed to ask your partner to get tested for HIV or AIDS. Don’t do rash things that you will regret for the rest of your life. Your health is in your hands. Take care of yourself.
Candidate of Biological Sciences A. LUSHNIKOVA. Based on materials from Scientific American.
The human immunodeficiency virus (HIV) was discovered in 1983 in two laboratories: at the Pasteur Institute in France, under the leadership of Luc Montagnier, and at the National Cancer Institute (USA), Robert Gallo and his colleagues. Now no one has any doubt that HIV causes a terrible disease, the “plague of the twentieth century” - AIDS (this name stands for “acquired immunodeficiency syndrome”). However, over more than a decade of research history, many mysteries have accumulated related to the development of this disease. For example, in some people infected with the immunodeficiency virus, signs of the disease appear after several years or do not appear at all. It turned out that there are people resistant to AIDS. How many such people are there, what characteristics do they have? Isn’t this the key to treating this terrible disease? The published article tries to answer these questions.
This is how the human immunodeficiency virus works. Inside it there is hereditary material - two RNA molecules, on the surface - shell proteins.
In a person with normal immunity, killer cells carrying the CD8 receptor molecule on their surface secrete hormone-like substances, chemokines.
If a person has a normal CCR5 gene, then under the control of this gene a protein is produced in target cells, which, together with another protein (CD4), serves as a “landing platform” for the immunodeficiency virus on the cell surface.
Needle in a haystack
Geneticists have long known about genes for resistance to certain viruses in mice, for example, the leukemia virus. But do similar genes exist in humans, and if so, what is their role in protecting against AIDS?
Stephen O'Brien and Michael Dean and their colleagues from the US National Cancer Institute have been searching for such genes in humans for many years.
In the early 80s, American scientists studied many people who, for one reason or another, could become infected with the immunodeficiency virus. They analyzed thousands of blood samples and discovered a seemingly inexplicable phenomenon: in 10-25% of those examined, the virus is not detected at all, and about 1% of HIV carriers are relatively healthy, their signs of AIDS are either absent or very weakly expressed, and their immune system All right. Is there really some kind of resistance to the virus in some people? And if so, what is it connected with?
Experiments on laboratory mice, rats, guinea pigs and rabbits have shown that resistance to various viral infections is often determined by a whole set of genes. It turned out that a similar mechanism determines resistance to the human immunodeficiency virus.
It is known that many genes are responsible for the production of certain proteins. It often happens that the same gene exists in several altered versions. Such “many-faced” genes are called polymorphic, and their variants can be responsible for the production of different proteins that behave differently in the cell.
By comparing susceptibility to viruses in mice carrying many different sets of genes and in mice with a small number of gene variants, the scientists concluded that the more genetically diverse the animals were, the less often they became infected with the virus. In this case, it can be assumed that in genetically diverse human populations, gene variants that determine resistance to HIV should occur quite often. An analysis of the incidence of AIDS among Americans of various nationalities revealed another feature: Americans of European descent are more resistant, while Africans and Asians have close to zero resistance. How can such differences be explained?
The answer to this question was proposed in the mid-80s by American virologist Jay Levy from the University of California at San Francisco. Levy and his colleagues tried to figure out which cells in the body the virus affects. They found that after the virus infects immune cells, they are easily recognized by another type of immune cell, called killer T cells. Killers destroy cells infected with the virus, preventing further replication of the virus. Killer cells carry a special molecule on their surface - the CD8 receptor. It, like a receiving antenna, “recognizes” signals from cells infected with a virus, and the killer cells destroy them. If all cells carrying the CD8 molecule are removed from the blood, then soon numerous viral particles are found in the body, the virus multiplies rapidly and lymphocytes are destroyed. Isn't this the key to the solution?
In 1995, a group of American scientists led by R. Gallo discovered substances that are produced in killer cells carrying CD8 molecules and suppress the replication of HIV. The protective substances turned out to be hormone-like molecules called chemokines. These are small proteins that attach to receptor molecules on the surface of immune cells when the cells are directed to a site of inflammation or infection. It remained to find the “gate” through which viral particles penetrate into immune cells, that is, to understand which receptors the chemokines interact with.
The Achilles heel of immune cells
Shortly after the discovery of chemokines, Edward Berger, a biochemist at the National Institute of Allergy and Infectious Diseases in Bethesda, USA, discovered a complex protein in the immune cells primarily affected by the virus (called target cells). This protein penetrates cell membranes and promotes the “landing” and fusion of viral particles with the membrane of immune cells. Berger named this protein "fusin", from the English word fusion - fusion. It turned out that fusin is related to chemokine receptor proteins. Does this protein serve as an “entry gate” for immune cells through which the virus penetrates? In this case, interaction with fusin of some other substance will block the access of viral particles to the cell: imagine that a key is inserted into the lock and the viral “loophole” disappears. It would seem that everything fell into place, and the relationship between chemokines - fusin - HIV was no longer in doubt. But is this pattern true for all types of cells infected by the virus?
While molecular biologists were unraveling the complex tangle of events occurring on the surface of cells, geneticists continued to search for genes for resistance to the immunodeficiency virus in humans. American researchers from the National Cancer Institute obtained cultures of blood cells and various tissues from hundreds of patients infected with HIV. DNA was isolated from these cells to search for resistance genes.
To understand how difficult this task is, it is enough to remember that human chromosomes contain about 100 thousand different genes. Testing even a hundredth of these genes would require several years of hard work. The pool of candidate genes narrowed markedly as scientists focused their attention on the cells that the virus first infects—the so-called target cells.
Equation with many unknowns
One of the features of the immunodeficiency virus is that its genes are introduced into the hereditary substance of the infected cell and “lurk” there for a while. While this cell grows and multiplies, viral genes are reproduced along with the cell's own genes. They then enter daughter cells and infect them.
From a variety of people at high risk of contracting HIV, we selected those infected with the virus and those who did not become carriers of HIV, despite constant contact with patients. Among the infected, we identified groups of relatively healthy people and people with rapidly developing signs of AIDS who suffered from concomitant diseases: pneumonia, skin cancer and others. Scientists have studied different options for the interaction of the virus with the human body. The different outcome of this interaction seemed to depend on the set of genes in the individuals studied.
It turned out that people resistant to AIDS have mutant, altered genes for the chemokine receptor - the molecule to which the virus attaches to in order to penetrate the immune cell. In them, contact between the immune cell and the virus is impossible, since there is no “receiving device”.
At the same time, Belgian scientists Michael Simpson and Marc Parmentier isolated the gene for another receptor. It turned out to be a protein that also serves as a receptor for binding HIV on the surface of immune cells. Only the interaction of these two receptor molecules on the surface of the immune cell creates a “landing pad” for the virus.
So, the main “culprits” for infecting cells with the immunodeficiency virus are receptor molecules called CCR5 and CD4. The question arose: what happens to these receptors during resistance to HIV?
In July 1996, American researcher Mary Curington from the Cancer Institute reported that the normal CCR5 receptor gene was found in only 1/5 of the patients she examined. A further search for variants of this gene among two thousand patients yielded surprising results. It turned out that in 3% of people who did not become infected with the virus, despite contacts with patients, the CCR5 receptor gene was altered, mutant. For example, when examining two New York homosexuals - healthy, despite contacts with infected people - it turned out that their cells produced a mutant CCR5 protein that was unable to interact with viral particles. Similar genetic variants were found only in Americans of European descent or people from West Asia, but “protective” genes were not found in Americans of African and East Asian descent.
It also turned out that some patients' resistance to infection is only temporary if they received the "saving" mutation from only one of their parents. Several years after infection, the number of immune cells in the blood of such patients decreased by 5 times, and against this background, complications associated with AIDS developed. Thus, only carriers of two mutant genes were invulnerable to HIV.
But in those with one mutant gene, signs of AIDS still developed more slowly than in carriers of two normal genes, and such patients responded better to treatment.
To be continued
Recently, researchers discovered varieties of extremely aggressive viruses. People infected with such viruses cannot be saved even by the presence of two mutant genes that provide resistance to HIV.
This forces us to continue the search for HIV resistance genes. Recently, American researchers O'Brien and M. Dean and their colleagues discovered a gene that, being present in people in only one copy, delays the development of AIDS for 2-3 years or more. Does this mean that a new weapon has appeared in the fight against the virus that causes AIDS? Most likely, scientists have lifted the curtain on the mysteries of HIV, and this will help doctors in the search for treatments for the “plague of the twentieth century.” Mutant genes have not been found in numerous populations of Afro-Asian Americans, but nevertheless there are small groups healthy people who have been in contact with infected people. This indicates the existence of other genes that protect the immune system from a terrible infection. So far, we can only assume that different human populations have developed their own genetic defense systems. Apparently, for other infectious diseases, including viral hepatitis, There are also genes for resistance to pathogen viruses.Now no geneticist doubts the existence of such genes for the immunodeficiency virus. Research in recent years has given hope of finding a solution to such a seemingly insoluble problem as the fight against AIDS. The future will show who will become the winner in the fight against HIV.
Science to healthcare
HOW TO TREAT AIDS. SEARCHING FOR A STRATEGY
The results of recent research have given thought not only to scientists and practitioners dealing with AIDS problems, but also to pharmacists. Previously, the focus was on combination treatment of infection directed against the virus. Drugs were used that prevent the virus from multiplying in cells: neviparin and atevirdine. This is the so-called group of HIV reverse transcriptase inhibitors, which prevent the hereditary material of the virus from being incorporated into the DNA of immune cells. They are combined with nucleoside analogues such as zidovudine, didanosine and stavudine, which alleviate the course of the disease. However, these drugs are toxic and have side effects on the body, so they cannot be considered optimal. They are increasingly being replaced by more advanced means of influencing HIV.
Recently, it has become possible to prevent viral particles from “landing” on the surface of cells. It is known that this process occurs due to the binding of the viral protein gp120 to cellular receptors. Artificially blocking HIV binding sites using chemokines should protect cells from HIV invasion. To do this, it is necessary to develop special blocking drugs.
Another way is to produce antibodies that will bind to CCR5 receptors, creating a “landing pad.” Such antibodies will prevent these receptors from interacting with the virus, preventing HIV from entering the cells. In addition, fragments of CCR5 molecules can be introduced into the body. In response to this, the immune system will begin to produce antibodies to this protein, which will also block the access of viral particles to it.
The most expensive way to secure viral particles is to introduce new mutant genes into immune cells. As a result, the assembly of the receptor for “landing” the virus on the surface of the “operated” cells will stop, and viral particles will not be able to infect such cells. Such protective therapy appears to be most promising in the treatment of AIDS patients, although it is very expensive.
When treating cancers that accompany AIDS, doctors most often resort to high doses of chemicals and irradiation of tumors, which disrupts hematopoiesis and requires transplantation of healthy bone marrow into patients. What if bone marrow taken from people who are genetically resistant to HIV infection is transplanted into a patient as donor hematopoietic cells? It can be assumed that after such a transplant, the spread of the virus in the patient’s body will be stopped: after all, donor cells are resistant to infection, since they do not have receptors that allow the virus to penetrate the cell membrane. However, this attractive idea is unlikely to be fully translated into practice. The fact is that immunological differences between the patient and the donor, as a rule, lead to rejection of the transplanted tissue, and sometimes to more serious consequences when donor cells attack foreign cells of the recipient, causing their massive death.
Dictionary
Killer T cells- immune cells that destroy virus-infected cells.
Cell receptors- special molecules on the surface that serve as an “identification mark” for viral particles and other cells.
Receptor gene- a gene responsible for the production of the corresponding protein.
Chemokines- hormone-like substances on the surface of immune cells that suppress the reproduction of the virus in the body.
Cell culture- cells that develop outside the body, in a test tube nutrient medium.
Mutant genes- altered genes that are unable to control the production of the desired protein.
Target cells- immune cells that are primarily attacked by the virus.
Figures and facts
Today there are 29 million people infected with the immunodeficiency virus in the world. 1.5 million people have already died from AIDS caused by this infection.
The region most affected by AIDS is Africa. In Europe, the leaders are Spain, Italy, France, and Germany. Since 1997, Russia has joined these countries. In the territory of the former USSR, HIV infection is distributed as follows: 70% - Ukraine, 18.2% - Russia, 5.4% - Belarus, 1.9% - Moldova, 1.3% - Kazakhstan, the rest - less than 0.5%.
By December 1, 1997, about 7,000 people infected with the immunodeficiency virus were officially registered in Russia, mainly through sexual transmission.
There are more than 80 centers for the prevention and control of AIDS in Russia and neighboring countries.